A semiconductor device of the present invention determines an overheat state by comparing a forward voltage drop of a temperature sensing diode with a reference voltage, and in addition includes a series regulator circuit composed of an amplifier and resistors, that receives the forward voltage drop of a temperature sensing diode and delivers an output voltage as temperature information to an external output terminal for temperature detection of the semiconductor device. Such a device can continuously detect the temperature of the semiconductor chip.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A semiconductor device for a power conversion circuit comprising: a semiconductor switch; a diode antiparallel connected to the semiconductor switch; and a temperature sensing diode that is disposed in a chip of the semiconductor switch; and a driver IC including: a current source that supplies constant current to the temperature sensing diode; an overheat protection circuit that turns the semiconductor switch OFF when a forward voltage drop of the temperature sensing diode reaches a predetermined value, the overheat protection circuit including a comparator; and a series regulator including an operational amplifier of which a non-inverting input terminal receives the forward voltage drop of the temperature sensing diode, and a first resistance and a second resistance connected to each other in series and provided between an output terminal of the operational amplifier and a ground, the second resistance being connected directly to the ground, the connecting point of the first resistance and the second resistance being directly connected to an inverting input terminal of the operational amplifier; wherein an output signal of the series regulator is delivered directly to an external output terminal for temperature detection of the semiconductor device to convert the temperature of the semiconductor switch into voltage so as to output the voltage from the semiconductor device for a power conversion circuit; wherein the series regulator and the external output terminal are distinct from the overheat protection circuit, wherein the output signal of the series regulator is not connected to the comparator of the overheat protection circuit, and wherein the output signal of the series regulator is output even in a state where the overheat protection circuit turns the semiconductor switch OFF.
2. The semiconductor device for a power conversion circuit according to claim 1 , wherein the overheat protection circuit turns the semiconductor switch OFF when the output voltage of the series regulator reaches a predetermined value.
3. The semiconductor device for a power conversion circuit according to claim 2 , wherein the semiconductor switch is an insulated gate type semiconductor element.
4. The semiconductor device for a power conversion circuit according to claim 1 , wherein the semiconductor switch is an insulated gate type semiconductor element.
5. The semiconductor device for a power conversion circuit according to claim 1 , wherein the connecting point of the first resistance and the second resistance is not connected to any other resistances.
6. A semiconductor device for a power conversion circuit comprising: a semiconductor switch; a diode antiparallel connected to the semiconductor switch; a temperature sensing diode that is disposed in a chip of the semiconductor switch; and a driver IC including: a current source that supplies constant current to the temperature sensing diode; an overheat protection circuit that turns the semiconductor switch OFF when a forward voltage drop of the temperature sensing diode reaches a predetermined value, the overheat protection circuit including a comparator; and a series regulator including an operational amplifier of which a non-inverting input terminal receives the forward voltage drop of the temperature sensing diode, and a first resistance and a second resistance connected to each other in series and provided between an output terminal of the operational amplifier and a ground, the second resistance being connected directly to the ground, the connecting point of the first resistance and the second resistance being directly connected to an inverting input terminal of the operational amplifier; and a switching circuit that turns ON with operation of the overheat protection circuit; wherein an output signal of the series regulator is delivered to the switching circuit and the switching circuit delivers a ground potential of a power supply of the driver IC when the switching circuit is in an ON state and the switching circuit delivers the output voltage of the series regulator when the switching circuit is in an OFF state, directly to an external output terminal for temperature detection of the semiconductor device to convert the temperature of the semiconductor switch into voltage so as to output the voltage from the semiconductor device for a power conversion circuit; wherein the series regulator and the external output terminal are distinct from the overheat protection circuit, wherein the output signal of the series regulator is not connected to the comparator of the overheat protection circuit, and wherein the output signal of the series regulator is output even in a state where the overheat protection circuit turns the semiconductor switch OFF.
7. The semiconductor device for a power conversion circuit according to claim 6 , wherein the semiconductor switch is an insulated gate type semiconductor element.
8. The semiconductor device for a power conversion circuit according to claim 6 , wherein the overheat protection circuit turns the semiconductor switch OFF when the output voltage of the series regulator reaches a predetermined value.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
March 1, 2013
March 29, 2016
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